Water feed system for boilers



July 16, 1946. R. R. WATERMAN WATER FEED SYSTEM FOR BOILERS Filed Dec.28, 1942 2 Sheets-Sheet 1 INVENTOR Xuss eZZR. Waterman 'July 16, 1946.R. R. WATERMAN WATER FEED SYSTEM FOR BOILERS 2 Sheets-Sheet 2 Filed Dec.28, 1942 Ez'g.3

INVENTOR Eu. sseZZJE. wazerman HTTYS Patented July 16, 1946 UNITEDSTATES PATENT OFFICE WATER FEED SYSTEM FOR BOILERS Russell R. Whitman,Lodi, Calif.

Application December 28, 1942, Serial No. 470,334

8 Claims. (Cl. 122-451) This invention relates to an automatic boilerfeed system and apparatus, one object being to provide a water feedsystenrfor the purpose which includes a steam operated boiler feed pumparranged for float-controlled operation only according to water levelconditions in the boiler, and only if steam is being withdrawn from theboiler, and which functions to maintain a subsbantially constant heatand water balance in the boiler. In other words, the pump doesnotnecessarily operate whenever steam is withdrawn, but on the other handwithdrawal of steam is a prerequisite to pump operation,

A further object is to arrange the steam pump in the system inconnection with a float actuated control valve unit mounted in a steamand water drum disposed exteriorly of but operatively connected to theboiler in flow circulating relationship therewith.

It is also an object of the invention to provide an improved apparatuswhich in one form causes a re-circulation of the water from the drumthrough an evaporator zone of the boiler when re-entering the drum, sothat steam in a wet condition enters the drum, as is desirable with thissystem.

A further object of the invention is to provide a simple and inexpensivesystem, and yet one which will be exceedingly efiective for the purposefor which it is designed.

These objects I accomplish by means oi. such structure and relativearrangement of parts as will fully appear by a perusal of the followingspecification and claims.

In the drawings similar characters of reference indicate correspondingparts in th several views: Figure 1 is a sectional elevation of one formof float control steam valve unit for operating the pump.

Figure 2 is a diagram of the system in which said unit is interposed.

Figure 3 is a sectional elevation of another form of float controlledvalve unit.

Figure 4 is a diagram of the system in which the last-named unit isinterposed.

- Referring now more particularly to the charac ters of reference on thedrawings, and particularly at present to Figs. 1 and 2 the systemincludes, with a coil boiler I, here shown as being of the so-cailedflash type, an evaporator unit indicated at 2 from which a steam line 3leads to a pressure-tight vertical drum disposed exteriorly of theboiler and in which steam and water separate, said line being connectedwith the drum near the top. A return water line 5 is here shown asleading from the bottom of the drum to the evaporator unit 2 at thebottom of the latter, with an ejector device 6 of suitable characterinterposed in said line 5 intermediate its ends and operated by steamsupplied from the boiler through a line i. A check valve 3 in the line 5prevents back fiow to the drum. By reason of this arrangement it will beseen that water forming in the separator drum from the steam suppliedthereto from the line 3 is auto matically returned to the evaporatorunit 2 and re-circulated therethrough.

A steam pump P includes a pumping member 5! and an operating member IS,the pumping member drawing water from a suitabl relatively inexhaustiblesource and delivering such Water to the boiler through a line I I. Steamto operate the member lll is fed thereto from a line l2 connected to thetop of the drum, with a float operated valve l3 interposed therein; themain steam take-on line l4 being connected with the line H and bypassingthe valve, and having throttle valve 55 therein. The exhaust line i2cifrom the pump member ill is connected to the line :4, the latter havinga pressure relief valve 16 therein set according to the difference inpressure in the main line and exhaust line, this being the samearrangement and for the same purpose as described in my copendingapplication for patent, Serial No. 463,886, filed October 26, 1942.

The preferred form of float controlled valve and pressure relief unitare shown in detail in Fig. 1. The valve comp-rises a tubular openendedpiston ll slidable in an elongated cylinder is mounted on and here shownas upstanding from the top of the drum t. A rod i9 is secured to anddepends from the valve ill and carries a float 23 disposed apredetermined distance below the level at which the steam line 3connects with the drum. In its lowest position or when the level of thecondensate in the drum is correspondingly lowered, the valve issupported on a shoulder 2| at the bottom of cylinder is. An annulargroove 22 in the periphery of the valve, and which communicates with theinterior of the same, then registers with the steam pump line l2.

The pressure relief valve I5 is mounted in the cylinder above the pistonvalve and comprises a spool-like plunger 23, yieldably pressed down byan adjustable spring 24 and normally seated against a top shoulder 25 inthe cylinder. The plunger when lifted a predetermined distance againstthe resistance of the spring by the steam pressure in the drum passingup through the piston valve I1, establishes communication between thedrum and the steam outlet pipe I4, allowing steam to pass out if thethrottle is open, without the necessity of causing the pump to operate,in the event that the float is lifted by a high condensate level and thepiston valve closes the line I2.

It Will thus be seen that steam may be withdrawn from the boiler withoutnecessarily placing the pump in operation, as long as the Water level inthe drum, which corresponds to the water level in the boiler, issufiiciently high to lift the float and maintain the piston valveclosed. At the same time the pump cannot operate unless steam is beingwithdrawn.

In the system shown in Figs. 3 and 4, the circulation of the condensatefrom the drum 4a. through evaporator unit 2a of the boiler coil Ia andback to the drum is the same as in the first described system, but themain steam outlet line Ma takes off directly from a superheater unit Sas shown in Fig. 4, and the float controlled valve for the steam pump ishere shown as being of somewhat difierent form and arrangement than inthe first described system.

In this case the drum is provided with a depending boss 25 having apassage 2'! communicating with a tube 28 secured on and upstanding fromthe base of the drum and open at its upper end to the interior of thedrum. A float 2?: surrounds the tube and is connected, by conventionalopposed levers 30 pivoted on the tube, with a valve stem 3| whichextends into the tube from its upper end and projects into the passage27. The stem on its lower end carries a double-ended valve 32 disposedin an enlarged portion 33 of the passage 21 and adapted to alternatelyengage seats 34 and 35 at the upper and lower ends respectively of saidenlarged portion. The steam line 36 leading to the operating member IDof the steam boiler feed pump communicates with the passage 21 above theseat 34; the exhaust line 31 from the member in communicates with saidpassage 2'! below the seat 35; while the steam return line 38 leads fromthe enlarged passage portion 33 between the valve seats to the'superheater unit S of the boiler near the lower end of said unit.

With the float and valve arrangement above described, the float whenlifted by the water in the drum, lowers the valve and causes it toengage the seat 35. When the float drops by a lowering of the condensatelevel, the valve is lifted and engages the upper seat 34. In operation,therefore, when the water level in the drum is at or near normal, thesteam in the drum, if the throttle is opened, cannot circulate throughthe pump but passes down through the tube 23 and then to the superheaterunit S through line 38. When the water level in the boiler and drum islowered by the use of steam, the line 38 is closed to the tube 28 by thevalve 32 engaging seat 34, but is opened to the line 3?, and steam thenpasses through said tube to the pump through line 36 and back to thesuperheater unit through lines 31 and 38.

The latter system is particularly designed for use in installation whendry steam only is desired, as for instance in cleaning and pressingestablishments. However, this type of system is also suitable for powerapplication when constructed for operating at relatively high pressures,and when superheated steam is desired.

From the foregoing description it will be readily seen that I haveproduced such a system as substantially fulfills the objects of theinvention as set forth herein.

While this specification sets forth in detail the present and preferredconstruction of the system, still in practice such deviation from suchdetail may be resorted to as do not form a departure from the spirit ofthe invention, as defined by the appended claims.

Having thu described my invention, what I claim as new and useful anddesire to secure by Letters Patent is:

1, A boiler water-feed system including with a boiler, a pump to feedwater to the boiler and including a steam operated unit, steam passagemeans leading to the unit from the boiler, means to allow of a flow ofsteam through said passage means only when steam is drawn from theboiler for use other than in the pump, and means controlled by waterlevel conditions in the boiler to prevent such flow unless the water isat a predetermined low level.

2. In a boiler water-feed system, a steam and water drum connected incirculating relation with the boiler, a pump to feed water to the boilerand including a steam operated unit, a tubular extension on the drumcommunicating with the steam zone thereof, a steam line leading to thepump unit from said extension, a valve. in the extension to control theflow of steam through said line, a water-engaging float connected to thevalve to operate the same by change of level of the water in the drum, amain steam outlet line connected to the extension in bypassing relationto the valve and to which the exhaust line from the pump unit isconnected, and a pressure relief valve in the extension and arranged inconnection with the outlet line to control the flow of steamtherethrough.

3. In a boiler water-feed system, a steam and water drum connected incirculating relation with the boiler, a pump to feed water to the boilerand including a steam operated unit, a tubular extension on the drumcommunicating with the steam zone thereof, a steam line leading to thepump unit from said extension on one side thereof, a tubular, open-endedpiston valve slidable in the extension to open or close the line to theextension, a water-engaging float connected to the valve to move thesame according to changes in level of the water in the drum, a mainsteam outlet line connected to the extension on the side and beyond thepiston valve and to which the exhaust of the pump unit is connected anda pressure relief valve in the extension beyond the piston valve andincluding a spring advanced plunger slidable in the extension and wheninactive closing the main line to the interior of the extension.

4. In a boiler Water-feed system, a steam and water drum connected incirculating relation with the boiler, a pump to feed water to the boilerand. including a steam operated unit, a member on and projecting fromthe drum and having a passage formed therein, a tubular element mountedon the drum and extending from said passage to maintain communicationbetween said passage and the steam zone of the drum, a feed steam lineleading to the pump unit from the steam zone of the drum, an exhauststeam line from the pump unit leading to the passage, a return lineleading to the boiler from the passage, and a Valve in the passagefloat-controlled by changes in level of the water in the drum to shutoil the exhaust line from the tubular element and return line when thewater level is relatively high and to shut ofi the return line from theelement and at the same time establish communication between the exhaustline and said return line when the water level is relatively low.

5. In a boiler Water-feed system, a steam and water drum connected incirculating relation with the boiler, a pump to feed water to the boilerand including a steam operated unit, a member on and projecting from thedrum and having a passage formed therein, a tubular element mounted inthe drum and extending from said passage to maintain communicationbetween said passage and the steam zone of the drum, a feed steam lineleading to the pump unit from the steam zone of the drum, the passagehaving an enlarged portion intermediate its ends and formed at itsopposite ends with opposed valve seats, a steam exhaust line from thepump unit leading to the passage beyond the seat furthest from thetubular element, a return line to the a boiler from the enlarged portionof the passage between the seats, a double-ended valve between andalternately engageable with the seats, a water engaging float in thedrum and means connecting the float and valve so that the latter engagesthe valve seat nearest the tubular element when the water level dropsand engages the other seat when the water level rises.

6. A structure as in claim 5, in which said last named means comprises astem connected to the valve and extending through the tubular element toits outer end, the float surrounding the latter and opposed leverspivoted intermediate their ends on the element and operatively connectedat one end to the stem and at the other end to the float.

'7. A boiler water feed system including, with a boiler, a drum separatefrom but connected in circulating relation with the boiler and receivingwater and steam therefrom, a steam driven pump adapted to pump feedwater from a source of water supply to the boiler, a steam line leadingfrom the drum to a point of use, a separate steam line leading from thedrum to the steam driven pump for operating the same, a steam lineleading from the pump to the first named steam line, and meansresponsive to the water level in the drum for controlling the flow ofsteam from the drum to the second named steam line for operating thepump.

8. A boiler water feed system including, with a boiler, a drum separatefrom but connected in circulating relation with the boiler and receivingwater and steam therefrom, a steam operated pump to feed water to theboiler, a steam circulating pipe system between the boiler, pump, andpoint of ultimate steam use, such system being so arranged that the pumpcan only operate when steam is being drawn from the boiler for use otherthan in operating the pump, while allowing use of the steamindependently of pump operation, and means responsive to the water levelin the drum for controlling the operation of the pump.

RUSSELL R. WATERMAN.

